class PolymorphicRelationship { final String relationTo; final String value; PolymorphicRelationship({ required this.relationTo, required this.value, }); factory PolymorphicRelationship.fromJson(Map json) { return PolymorphicRelationship( relationTo: json['relationTo'] as String, value: json['value'] as String, ); } Map toJson() { return { 'relationTo': relationTo, 'value': value, }; } }